1. Field of the Invention
The present invention relates to a photosensitive resin composition, and more particularly, to a photosensitive resin composition which adjusts line width and height of a pattern without difficulty, forms a linear pattern, provides good transmittance and is adequate to form an over coating layer (OCL) of a color filter.
2. Description of the Related Art
FIG. 1 is a sectional view of a conventional color filter array of a semiconductor device. Main parts of a conventional CMOS image sensor for collecting light are illustrated in FIG. 1.
As shown therein, a first over coating layer 2 is formed on a semiconductor substrate 1 which has finished shallow trench isolation and a passivation process. Color filter arrays 3a, 3b and 3c are formed on the first over coating layer 2. A second over coating layer 4 is formed on the color filter arrays 3a, 3b and 3c to provide a planar surface and protect a device. Micro lenses 5 are formed corresponding to the respective color filter arrays 3a, 3b and 3c. 
The red, green and blue color filters 3a, 3b and 3c include photoresist (Korean Patent First Publication No. 2006-0063475) which is pigment-dispersed to absorb light at particular wavelengths. Polymer resin is commonly used as the material of the micro lenses 5.
If the color filters 3a, 3b and 3c are formed in a size of 3.2 um and below with the foregoing method, boundaries between the color filters 3a, 3b and 3b become unclear, thereby lowering uniformity in the size and height of the pattern. As the color filters 3a, 3b and 3c have different sizes, light may be incident to wrong optical paths. Then, light may not be sensed or interference phenomena occur in neighboring color filters 3a, 3b and 3c, thereby hardly realizing a high quality image from a CMOS image sensor.